Electronically controlled sway bar damping link

ABSTRACT

A sway bar system is described. The sway bar system includes a sway bar having a first end and a second end. The sway bar system further includes a first electronically controlled damper link which is coupled to the first end of the sway bar. The first electronically controlled damper link is configured to be coupled a first location of a vehicle. The sway bar system also has a second link which is coupled to the second end of the sway bar. The second link is configured to be coupled a second location of the vehicle.

CROSS-REFERENCE

This application claims priority to and the benefit of co-pending U.S.Provisional Patent Application 62/566,022 filed on Sep. 29, 2017,entitled “ELECTRONICALLY CONTROLLED SWAY BAR DAMPING LINK” by PhilipTsiaras et al, the disclosure of which is hereby incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

Embodiments of the present technology relate generally to sway bar on avehicle.

BACKGROUND

A sway bar (anti-sway bar, roll bar, anti-roll bar, stabilizer bar) is apart of an automobile suspension that reduces the body roll of avehicle. The sway bar is basically a torsion spring that resists bodyroll motions. Often, it is formed from a cylindrical steel bar patternedin a “U” shape. A conventional sway bar assembly includes a sway bar andalso includes two end links. Typically, the first of the two end linksis flexibly coupled to one end of the sway bar, and the second of thetwo ends links flexibly coupled to the other end of the sway bar. Eachof the two end links are then connected to a location on the vehiclenear a wheel or axle at respective left and right sides of thesuspension for the vehicle. As a result, when the left and right sidesof the suspension move together, the sway bar rotates about its mountingpoints. However, when the left and right sides of the suspension moverelative to one another, the sway bar is subjected to torsion and forcedto twist. The twisting of the sway bar transfers the forces between aheavily-loaded suspension side (the side of the vehicle subjected tomore roll movement force than the other side of the vehicle) to theopposite, lesser-loaded, suspension side (the side of the vehiclesubjected to lesser roll movement force than the other side of thevehicle).

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present invention are illustrated by way of example, andnot by way of limitation, in the accompanying drawings, wherein:

FIG. 1A is a perspective view of a sway bar system including at leastone electronically controlled damper link, in accordance with anembodiment of the present invention.

FIG. 1B is a perspective view of a sway bar system including at leastone electronically controlled damper link installed in a vehicle, inaccordance with an embodiment of the present invention.

FIG. 1C is a perspective view of a sway bar system including twoelectronically controlled damper links coupled to a vehicle, inaccordance with an embodiment of the present invention.

FIG. 2A is a cutaway schematic view of an electronically controlleddamper link in a state of compression, in accordance with an embodimentof the present invention.

FIG. 2B is a cutaway schematic view of an electronically controlleddamper link in a state of rebound, in accordance with an embodiment ofthe present invention.

FIG. 3A is a cutaway schematic view of a twin tube electronicallycontrolled damper link in compression, in accordance with an embodimentof the present invention.

FIG. 3B is a cutaway schematic view of a twin tube electronicallycontrolled damper link in rebound, in accordance with an embodiment ofthe present invention.

FIG. 4 is a perspective view of an inner body portion of a first dampercylinder within a larger outer body portion of a second damper cylinder,in accordance with an embodiment of the present invention.

FIG. 5 is an enlarged section view showing the remotely operable valvein the open position, in accordance with an embodiment of the presentinvention.

FIG. 6 is a section view showing the valve of FIG. 5 in a closedposition, in accordance with an embodiment of the present invention.

FIG. 7 is a section view showing the valve of FIG. 5 in a locked-outposition, in accordance with an embodiment of the present invention.

FIG. 8 is a schematic diagram showing a control arrangement for aremotely operated valve, in accordance with an embodiment of the presentinvention.

FIG. 9 is a schematic diagram showing another control arrangement for aremotely operated valve, in accordance with an embodiment of the presentinvention.

FIG. 10 is a graph showing some operational characteristics of thearrangement of FIG. 7, in accordance with an embodiment of the presentinvention.

The drawings referred to in this description should be understood as notbeing drawn to scale except if specifically noted.

DESCRIPTION OF EMBODIMENTS

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various embodiments of thepresent invention and is not intended to represent the only embodimentsin which the present invention is to be practiced. Each embodimentdescribed in this disclosure is provided merely as an example orillustration of the present invention, and should not necessarily beconstrued as preferred or advantageous over other embodiments. In someinstances, well known methods, procedures, objects, and circuits havenot been described in detail as not to unnecessarily obscure aspects ofthe present disclosure.

In the following discussion, embodiments of the present sway bar system(also referred to herein as an “E-Sway Bar” system) are described indetail. As will be described below, embodiments of the present sway barsystem advantageously enable remote input (e.g., manual remote input orautomatic remote input) to manipulate the stiffness of the present swaybar system. The stiffness of the sway bar system can be thought of as,for example, a driver's (or passenger's) perception of the “rollstability” of the vehicle. In other words, the perception of the driver(or passenger) of the vehicle for the vehicle to resist or allow “rollmotion”. As one example, when riding in a vehicle (e.g., a sports car)which appears to provide significant resistance to a rolling motion ofthe vehicle, it can be said that the vehicle has a “stiff” sway barsystem. As another example, when riding in a vehicle (e.g., a motorhomeor bus) which appears to not provide significant resistance to a rollingmotion of the vehicle, it can be said that the vehicle has a “soft” swaybar system. It will be understood that a “soft” sway bar system isdesired in various conditions. For example, a soft sway bar systemprovides better comfort during rock crawling and some slow drivingactivities. Further, it will be understood that “stiff” sway bar systemis desired in various conditions. For example, it will be understoodthat a stiff sway bar system provides increased handling and controlduring high speed cornering and various racing activities.

Further, in the following discussion, the term “active”, as used whenreferring to a valve or damping component, means adjustable,manipulatable, etc., during typical operation of the valve. For example,an active valve can have its operation changed to thereby alter acorresponding damping characteristic from a “soft” damping setting to a“firm” damping setting by, for example, adjusting a switch in apassenger compartment of a vehicle. Additionally, it will be understoodthat in some embodiments, an active valve may also be configured toautomatically adjust its operation, and corresponding dampingcharacteristics, based upon, for example, operational informationpertaining to the vehicle and/or the suspension with which the valve isused. Similarly, it will be understood that in some embodiments, anactive valve may be configured to automatically adjust its operation,and corresponding damping characteristics, to provide damping based uponreceived user input settings (e.g., a user-selected “comfort” setting, auser-selected “sport” setting, and the like). Additionally, in manyinstances, an “active” valve is adjusted or manipulated electronically(e.g., using a powered solenoid, or the like) to alter the operation orcharacteristics of a valve and/or other component. As a result, in thefield of suspension components and valves, the terms “active”,“electronic”, “electronically controlled”, and the like, are often usedinterchangeably.

In the following discussion, the term “manual” as used when referring toa valve or damping component means manually adjustable, physicallymanipulatable, etc., without requiring disassembly of the valve, dampingcomponent, or suspension damper which includes the valve or dampingcomponent. In some instances, the manual adjustment or physicalmanipulation of the valve, damping component, or suspension damper,which includes the valve or damping component, occurs when the valve isin use. For example, a manual valve may be adjusted to change itsoperation to alter a corresponding damping characteristic from a “soft”damping setting to a “firm” damping setting by, for example, manuallyrotating a knob, pushing or pulling a lever, physically manipulating anair pressure control feature, manually operating a cable assembly,physically engaging a hydraulic unit, and the like. For purposes of thepresent discussion, such instances of manual adjustment/physicalmanipulation of the valve or component can occur before, during, and/orafter “typical operation of the vehicle”.

It should further be understood that a vehicle suspension may also bereferred to using one or more of the terms “passive”, “active”,“semi-active” or “adaptive”. As is typically used in the suspension art,the term “active suspension” refers to a vehicle suspension whichcontrols the vertical movement of the wheels relative to vehicle.Moreover, “active suspensions” are conventionally defined as either a“pure active suspension” or a “semi-active suspension” (a “semi-activesuspension” is also sometimes referred to as an “adaptive suspension”).In a conventional “pure active suspension”, a motive source such as, forexample, an actuator, is used to move (e.g. raise or lower) a wheel withrespect to the vehicle. In a “semi-active suspension”, no motiveforce/actuator is employed to adjust move (e.g. raise or lower) a wheelwith respect to the vehicle. Rather, in a “semi-active suspension”, thecharacteristics of the suspension (e.g. the firmness of the suspension)are altered during typical use to accommodate conditions of the terrainand/or the vehicle. Additionally, the term “passive suspension”, refersto a vehicle suspension in which the characteristics of the suspensionare not changeable during typical use, and no motive force/actuator isemployed to adjust move (e.g. raise or lower) a wheel with respect tothe vehicle. As such, it will be understood that an “active valve”, asdefined above, is well suited for use in a “pure active suspension” or a“semi-active suspension”.

In some embodiments of the present invention, the damping characteristicof at least one damper is obtained by controlling a remotely adjustableactive valve (may also be referred to as a remotely adjustableelectronic valve or, more concisely, as just an active valve) of thedamper, wherein the remotely adjustable active valve utilizes arelatively small solenoid (using relatively low amounts of power) togenerate relatively large damping forces. Examples of such an activevalve are described and shown in U.S. Pat. Nos. 9,120,362; 8,627,932;8,857,580; 9,033,122; and 9,239,090 which are incorporated herein, intheir entirety, by reference.

Referring now to FIG. 1A, a perspective view of a sway bar system 100including a sway bar 12 and two electronically controlled damper links,14L and 14R, is shown in accordance with an embodiment of the presentinvention. For purposes of clarity, in FIG. 1A, electronicallycontrolled damper link 14L and electronically controlled damper link 14Rare shown slightly separated from sway bar 12 in order to more clearlydepict the location, 13L, where electronically controlled damper link14L couples to sway bar 12, and to more clearly depict the location,13R, where electronically controlled damper link 14R couples to sway bar12. In various embodiments of present sway bar system 100, an upperportion of electronically controlled damper link 14L includes a bushing,or similar coupling feature, to readily enable coupling ofelectronically controlled damper link 14L to, for example, 13L of swaybar 12. Similarly, in various embodiments of present sway bar system100, an upper portion of electronically controlled damper link 14Rincludes a bushing, or similar coupling feature, to readily enablecoupling of electronically controlled damper link 14R to, for example,13R of sway bar 12. It should be noted that present sway bar system 100is not limited solely to the use of a bushing for coupling one or bothof electronically controlled damper link 14L and electronicallycontrolled damper link 14R to sway bar 12.

With reference still to FIG. 1A, in various embodiments of present swaybar system 100, a lower portion of electronically controlled damper link14L includes an eyelet, or similar coupling feature, to readily enablecoupling of electronically controlled damper link 14L to a location on avehicle. Similarly, in various embodiments of present sway bar system100, a lower portion of electronically controlled damper link 14Rincludes an eyelet, or similar coupling feature, to readily enablecoupling of electronically controlled damper link 14R to a location on avehicle. It should be noted that present sway bar system 100 is notlimited solely to the use of an eyelet for coupling one or both ofelectronically controlled damper link 14L and electronically controlleddamper link 14R to a vehicle.

Although the embodiment of FIG. 1A, depicts sway bar system 100 havingtwo electronically controlled damper links 14L and 14R, in anotherembodiment of the present invention, sway bar system 100 includes only asingle electronically controlled damper link (e.g., only 14L or only14R). In such an embodiment, an electronically controlled damper link(e.g., 14L or 14R) is coupled to one end (e.g., a first end) of sway bar12, and, for example, a conventional end link is coupled to the otherend (e.g., a second end) of sway bar 12. Hence, sway bar system 100 ofthe present invention is well suited to embodiments in which one end ofsway bar 12 has an electronically controlled damper link (e.g., 14L or14R) coupled thereto, and also to embodiments in which both ends of swaybar 12 have an electronically controlled damper link (e.g., 14L and 14R,respectively) coupled thereto. Additionally, for purposes of concisenessand clarity, portions of the following description may refer to anelectronically controlled damper link as “electronically controlleddamper link 14”, instead repeating the same description for each ofelectronically controlled damper link 14L and electronically controlleddamper link 14R. It should be noted that such portions of thedescription are applicable to either electronically controlled damperlink 14L or electronically controlled damper link 14R, as shown in swaybar system 100 of FIG. 1A. Further, the present description will pertainto embodiments in which one end of sway bar 12 has an electronicallycontrolled damper electronically controlled damper link (e.g., 14L or14R) coupled thereto, and also to embodiments in which both ends of swaybar 12 have an electronically controlled damper link (e.g., 14L and 14R,respectively) coupled thereto.

With reference now to FIG. 1B, a perspective view 150 is provided ofsway bar system 100, of FIG. 1A, installed in a vehicle, in accordancewith an embodiment of the present invention. In the embodiment of FIG.1B, sway bar 12 and at least one electronically controlled damper link14L is shown installed in a vehicle 152. In embodiments of the presentinvention, sway bar system 100 is coupled to a vehicle with at least oneend of sway bar 12 coupled to the vehicle by an electronicallycontrolled damper link (e.g., 14L or 14R). That is, unlike conventionalsway bar assemblies, in embodiments of the present invention, sway barsystem 100 has one end of sway bar 12 coupled to a vehicle by anelectronically controlled damper link (e.g., 14L or 14R). In otherembodiments of the present invention, sway bar system 100 has both endsof sway bar 12 coupled to a vehicle by an electronically controlleddamper link (e.g., 14L and 14R, respectively). As a result, and as willbe described further below, the “stiffness” provided by sway bar system100 can be remotely controlled by controlling the stiffness orcompliance of one or both of electronically controlled damper links 14Land 14R coupling sway bar 12 to a vehicle. Importantly, FIG. 1B furthershows a cable 111. Cable 111 is used to provide input to electronicallycontrolled damper link 14. Such input is used to control the dampingcharacteristics of electronically controlled damper link 14. In variousembodiments, as are described below in detail, such input may consist ofelectrical input (based upon, e.g., user input, sensors-derived data, orany of various other sources) used to control an electronic valve withinelectronically controlled damper link 14 and, correspondingly, controlthe damping characteristics of electronically controlled damper link 14.Embodiments of the present sway bar system 100 are also well suited tousing a wireless signal (in addition to, or in lieu of, cable 111) tocontrol a valve or other component of electronically controlled damperlink 14 such that, ultimately, the damping characteristic ofelectronically controlled damper link 14 is controllable.

Referring now to FIG. 1C, a perspective view is provided of sway barsystem 100 having electronically controlled damper link 14L coupled to afirst end of sway bar 12 at location 13L. In the embodiment of FIG. 1C,sway bar system 100 further includes electronically controlled damperlink 14R coupled to a second end of sway bar 12 at location 13R.Additionally, as schematically depicted in FIG. 1C, in the presentembodiment, electronically controlled damper link 14L is coupled tovehicle 152, and electronically controlled damper link 14R is coupled tovehicle 152. In various embodiments of the present invention,electronically controlled damper link 14L and electronically controlleddamper link 14R are coupled to vehicle 152 at a location, for example,near a wheel or axle of vehicle 152 at respective left and right sidesof vehicle 152. It will be understood that when the left and right sidesof the suspension of vehicle 152 move relative to one another, sway bar12 of sway bar system 100 is subjected to torsion and forced to twist.The twisting of sway bar 12 will transfer forces between aheavily-loaded suspension side of vehicle 152 to the opposite,lesser-loaded, suspension side of vehicle 152.

Referring now to FIG. 2A, a cutaway schematic view 11 of electronicallycontrolled damper link 14 in a state of compression is shown, inaccordance with an embodiment of the present invention. Referring alsoto FIG. 2B, a cutaway schematic view 41 of electronically controlleddamper link 14 in a state of rebound is shown, in accordance with anembodiment of the present invention. As FIG. 2A and FIG. 2B are similar,other than their state of operation (compression in FIG. 2A and reboundin FIG. 2B), the components of FIG. 2A and FIG. 2B will be discussed atthe same time. However, it should be appreciated that various fluid flowthrough various valves and components of electronically controlleddamper link 14 may be in an opposite direction in FIG. 2A when comparedto FIG. 2B. Further, it will be understood that the location of certain“inlet valves” or “outlet valves”, and the applicability of terms suchas “inlet” or “outlet”, and the like, as applied to the various valvesand/or components, may vary in FIG. 2A when compared to FIG. 2B.

Referring again to FIG. 2A and also to FIG. 2B, electronicallycontrolled damper link 14 includes a damper cylinder 28 with a shaft 24and a damping piston 25. As shown, in FIG. 2A, shaft 24 and dampingpiston 25 are coupled to each other. It will be understood that,typically, damper cylinder 28 encloses a damper cylinder chamber(sometimes referred to as the damper cylinder volume). It will furtherbe understood that damping piston 25 and shaft 24 are, typically,movable into and out of the damper cylinder chamber and that dampingpiston 25 and shaft 24 move axially with respect to damper cylinder 28.Damper cylinder 28 is typically at least partially filled with a dampingfluid. As will be understood, during operation of the damper, thedamping fluid is metered from one side of damping piston 25 to the otherside by passing through valve flow opening 22 traversing through valve200 (which is described in detail below) and, optionally, throughopenings in digressive piston 23. In one such embodiment, openings areformed in damping piston 25. It should be noted that for purposes ofclarity, valve 200 is depicted schematically in FIG. 2A, FIG. 2B, FIG.3A and FIG. 3B. A detailed illustration of at least one embodiment ofvalve 200 is provided at FIG. 5, FIG. 6 and FIG. 7. Similarly, adetailed description of at least one embodiment of valve 200 is providedbelow and in conjunction with the discussion of FIG. 5, FIG. 6 and FIG.7. Additionally, although valve 200 is referred to as a single valve,embodiments of the present invention are also well suited to the use ofmore than one valve to comprise “valve 200”. For purposes of brevity andclarity, however, the present discussion will refer to a valve 200 as asingle valve.

In embodiments of sway bar system 100, fluid flow through variousopenings within the electronically controlled damper 14 is restrictedusing, for example, shims which partially obstruct the flow paths ineach direction in digressive piston 23 and also available flow paths indamping piston 25. By selecting shims having certain desired stiffnesscharacteristics, the dampening effects caused by digressive piston 23can be increased or decreased and dampening rates can be differentbetween the compression and rebound strokes of damping piston 25. Forexample, the shims are configured to meter rebound flow from the reboundportion of the to the compression portion of damper cylinder 28, or tometer compression flow from the compression portion of damper cylinder28 to the rebound portion. Embodiments of the present invention are wellsuited to metering fluid flow during compression, during rebound, orduring both compression and rebound.

A fluid reserve cylinder 211 is in fluid communication with the dampercylinder 28 for receiving and supplying damping fluid as shaft 24 movesin and out of damper cylinder 28. Fluid reserve cylinder 211 is in fluidcommunication with damper cylinder 28 via a fluid path 32. Asillustrated, for example, in FIG. 2A and FIG. 2B, fluid reserve cylinder211 at least partially encloses a fluid reservoir chamber 26 and a gaschamber 27. As also shown in FIG. 2A and FIG. 2B, fluid reserve cylinder211 also includes and encloses an internal floating piston (IFP) 33. IFP33 is disposed within fluid reserve cylinder 211 and movably and fluidlyseparates fluid reservoir chamber 26 and gas chamber 27. IFP 33 can bedescribed as having gas chamber 27 on the “backside” thereof (sometimesreferred to as the “blind end” of IFP 33). Additionally, IFP 33 can alsobe described as having fluid reservoir chamber 26 on the “frontside”thereof

With reference still to FIG. 2A and FIG. 2B, it will be understood thatgas within gas chamber 27 is compressible as fluid reservoir cylinder 26(on the “frontside” of IFP 33) fills with damping fluid due to movementof shaft 24 and damping piston 25 into damper cylinder 28. Certainfeatures of reservoir-type dampers are shown and described in U.S. Pat.No. 7,374,028, which is incorporated herein, in its entirety, byreference. As described above, in various embodiments, sway bar system100 will have an upper portion of electronically controlled damper 14coupled to sway bar 12 through the use of a bushing. Similarly, invarious embodiments, a lower portion of upper portion of electronicallycontrolled damper 14 (e.g., a portion of shaft 24 (opposite dampingpiston 25) which extends outside of damper cylinder 28) is supplied withan eyelet 29 to readily enable coupling of electronically controlleddamper 14 to a part of the vehicle. As a result, as shaft 24 and dampingpiston 25 move into damper cylinder 28 (e.g., during compression),depending upon the setting of the valve 200, the damping fluid cancontrol the relative speed of movement between sway bar 12 and thevehicle mounting location. Specifically, the incompressible dampingfluid moving through the various flow paths provided in the dampingpiston 25 and/or the metered bypass 44 (see for example FIGS. 3A and3B), as will be described herein, can be used to control the dampingcharacteristics of electronically controlled damper 14. In one example,as shaft 24 and damping piston 25 move out of the damper cylinder 28(e.g., during extension or “rebound”) damping fluid is metered throughthe flow path 32, valve flow opening 22, and valve 200, and the flowrate and corresponding stiffness of electronically controlled damper 14is thereby controlled. Once again, it should be noted that embodimentsof the present invention are well suited to metering fluid flow duringcompression, during rebound, or during both compression and rebound.Further, it should be noted that embodiments of the present inventionare also well suited to various other structures and arrangementsincluding, but not limited to, main piston damping, piston bypassconfigurations, and various other damper configurations.

Referring now to FIG. 3A, a cutaway schematic view 57 of a twin tubeelectronically controlled damper link 14 in a compression state is shownin accordance with an embodiment of the present invention. Similarly, asabove, FIG. 3B is a cutaway schematic view 65 of a twin tubeelectronically controlled damper link 14 in a rebound state is shown inaccordance with an embodiment of the present invention. As such, thecomponents of FIGS. 3A and 3B will be discussed at the same time (andthose components that overlap with FIG. 2A or 2B will not bere-addressed). However, it should be appreciated that the fluid flowthrough valve 200 will be in the opposite direction when comparing FIGS.3A and 3B. Thus, for example, there may be an inlet valve in onelocation, and an outlet valve at different location, or a valve that canoperate as both an inlet and an outlet.

In general, the twin tube structure, of FIG. 3A and FIG. 3B, allows thebypass 44 to provided fluid connectivity between the lower portion ofdamper cylinder 28 below damping piston 25 and the upper portion ofdamper cylinder 28 above damping piston 25 (as oriented).

In one embodiment, the valve 200 is a remotely and electronicallycontrolled valve. In one such embodiment, the control of valve 200 ismade from a remote location such as in the cab of the vehicle to whichsway bar system 100 is coupled.

As will be described in detail below, valve 200 of electronicallycontrolled damper link 14 allows for fast acting, proportional changesto compression and/or rebound damping rates. Moreover, the damping ofelectronically controlled damper link 14 can vary from fully locked outto a compliant state. Thus, electronically controlled damper link 14replaces a conventional end link. By providing fast acting, proportionalchanges to compression and rebound damping, electronically controlleddamper link 14 is significantly superior in performance and operation toa conventional end link device. Furthermore, electronically controlleddamper link 14 enables the stiffness or compliance of sway bar system100 to be remotely controlled by controlling the stiffness or complianceof electronically controlled damper link 14. For example, in variousembodiments of the present invention, electronically controlled damperlink 14 will, for example, increase its dampening, and, correspondingly,increase the stiffness of sway bar system 100. In various embodiments ofthe present invention, such increased stiffness of sway bar system 100is advantageous, for example, during cornering, as vehicle speed rises,when vehicle roll is detected, and the like.

Conversely, in various embodiments of the present invention,electronically controlled damper link 14 will, for example, decrease itsdampening, and, correspondingly, decrease the stiffness of sway barsystem 100. In various embodiments of the present invention, suchdecreased stiffness of sway bar system 100 is advantageous, for example,for rough terrain, slow speeds, rock crawling, and the like.

Moreover, in various embodiments of sway bar system 100, adjustments aremade to electronically controlled damper link 14 to obtain a stiff orsoft sway bar feel, wherein such a “sway bar feel” is selectable by therider and/or driver of the vehicle to which sway bar system 100 iscoupled. Additionally, in various embodiments of sway bar system 100,settings are used to control understeer/oversteer, etc. For example,there may be a number of presets that an operator of the vehicle, towhich sway bar system 100 is coupled, can select to adjust the dampingcharacteristics of electronically controlled damper link 14 based on theterrain being covered, the speed being driven, and the like. Further, invarious embodiments of the present sway bar system, such presets areselectable and changeable on the fly, e.g., throughout a drive, withoutthe operator having to stop the vehicle.

In one embodiment of sway bar system 100, the damping characteristics ofelectronically controlled damper link 14 are automatically adjusted by aprocessor and are based on one or more inputs received at the processor.For example, in one embodiment of sway bar system 100, steering inputs,vehicle roll, speed, terrain, and the like are detected and/or monitoredvia one or more sensors on or about the vehicle to which sway bar system100 is coupled. Sensors which are utilized to monitor various parametersinclude, but not limited to, accelerometers, sway sensors, suspensionchanges, visual identification technology (e.g., single or multispectrum cameras), driver input monitors, steering wheel turningsensors, and the like.

For example, one embodiment of sway bar system 100 uses an inertialmeasurement unit (IMU) to sense rough terrain. One embodiment of swaybar system 100 has an attitude and heading reference system (AHRS) thatprovides 3D orientation integrating data coming from inertialgyroscopes, accelerometers, magnetometers and the like. For example, inyet another embodiment of sway bar system 100, the AHRS is a GPS aidedMicroelectromechanical systems (MEMS) based IMU and static pressuresensor. It should be noted that in various embodiments of sway barsystem 100, various sensor-derived data, user input, IMU data, AHRSdata, and the like, is ultimately used (e.g., by passing a correspondingsignal through cable 111 of FIG. 1B to electronically controlled damperlink 14) to control the damping characteristics of electronicallycontrolled damper link 14.

As discussed herein, electronically controlled damper link 14 includesIFP 33 which, in one embodiment of sway bar system 100, is placed on therebound side to create more compression damping without causingcavitation. When a check valve opens, the damping force ofelectronically controlled damper link 14 will be lower thereby reducingthe chances of cavitation.

In one embodiment of sway bar system 100, by reducing the diameter (seee.g., reference number 19 of FIG. 2A and FIG. 2B) of shaft 24, reactionforces of shaft 24 will also be reduced. Additionally, in embodiments ofsway bar system 100, the diameter of damper cylinder 28 is reduced. Byreducing the diameter of damper cylinder 28, the damper cylinder volumecorresponding to damper cylinder 28 is also reduced. Hence, changes inthe diameter of damper cylinder 28 ultimately alter the ratio betweenthe damper cylinder volume of damper cylinder 28 and the flow area of,for example, valve 200. Reducing the damper cylinder volume with respectto the flow area of valve 200 will provide a softer initial pressuresetting in gas chamber 27.

In various embodiments of sway bar system 100, damping characteristicsof electronically controlled damper link 14 are altered by changing adamping fluid flow path. As one example, depending upon the type ofvalve 200, flow path 32 can be changed. For example, the damping fluidflow path in a twin tube embodiment (see, e.g., FIG. 3A and FIG. 3B) isdifferent from the damping fluid flow path in a non-twin tube embodiment(see, e.g., FIG. 2A and FIG. 2B).

In various embodiments of sway bar system 100, damping characteristicsof electronically controlled damper link 14 are altered by selectivelycontrolling the flow of damping fluid through damping piston 25. Forexample, in one embodiment, electronically controlled damper link 14includes a damping piston 25 which is a solid piston with no valvingtherethrough (as shown in FIG. 2A). However, in another embodiment ofsway bar system 100, electronically controlled damper link 14 includes adamping piston 25 which is a digressive piston (as shown in FIG. 2B). Inan embodiment of sway bar system 100 as depicted in FIG. 2B, by having adigressive piston on both the base valve and damping piston 25, a betterhigh speed blow off is achieved.

Referring now to FIG. 4 (and also to FIG. 1A), as stated above, inembodiments of sway bar system 100, the diameter of damper cylinder 28is reduced. By reducing the diameter of damper cylinder 28, the dampercylinder volume corresponding to damper cylinder 28 is also reduced.Hence, changes in the diameter of damper cylinder 28 ultimately alterthe ratio between the damper cylinder volume of damper cylinder 28 andthe flow area of, for example, valve 200. In FIG. 4 (and also referringto FIG. 2A and FIG. 2B), a perspective view 78 of an inner body portionof a first damper cylinder 71 within a larger outer body portion of asecond damper cylinder 73 is shown in accordance with an embodiment ofthe present invention. In other words, the damper cylinder diameter 30of damper cylinder 28 is reduced by fitting a smaller damper cylinder(e.g., first damper cylinder 71) inside of the larger damper cylinder(e.g., second damper cylinder 73). A new body cap and seal head is thenused to attach damper cylinder 71 and damper cylinder 73.

In one embodiment, shaft size 19 of shaft 24 is also reduced. The changein damper cylinder diameter 30 changes the ratio between damper cylindervolume and the flow area of valve 200. For example, when valve 200remains the same and damper cylinder volume is decreased, electronicallycontrolled damper link 14 will have a softer decoupled setting. Invarious embodiments of sway bar system 200, the ratio of damper cylindervolume of damper cylinder 28 to the flow area of valve 200 can be tunedby changing one or both of damper cylinder volume and the flow area ofvalve 200.

FIGS. 5, 6 and 7 are enlarged views showing the remotely controllablevalve 200 in various positions. In FIG. 5, the remotely controllablevalve 200 is in a damping-open position (and a fluid path (denoted by201 of FIG. 5) is obtained) thereby permitting operation in acompression stroke of electronically controlled damper link 14. Theremotely controllable valve 200 includes a valve body 204 housing amovable piston 205 which is sealed within the body. Three fluidcommunication points are provided in the body including an inlet 202 andoutlet 203 for fluid passing through the remotely controllable valve 200as well as an inlet 225 for control fluid as will be described herein.Extending from a first end of the piston 205 is a shaft 210 having acone-shaped member 212 (other shapes such as spherical or flat, withcorresponding seats, will also work suitably well) disposed on an endthereof. The cone-shaped member 212 is telescopically mounted relativeto, and movable on, the shaft 210 and is biased in an extended position(FIG. 6) due to a spring 215 coaxially mounted on the shaft 210 betweenthe cone-shaped member 212 and the piston 205. Due to the spring 215biasing, the cone-shaped member 212 normally seats itself against a seat217 formed in an interior of the valve body 204. In the damping openposition shown however, fluid flow through the damper link 14 hasprovided adequate force on the cone-shaped member 212 to urge itbackwards, at least partially loading the spring 215 and creating fluidpath 201 from the damper link 14 into a rebound area of the dampercylinder 141 as shown in FIG. 2A. The characteristics of the spring 215are typically chosen to permit the remotely controllable valve 200 (e.g.cone-shaped member 212) to open at a predetermined bypass pressure, witha predetermined amount of control pressure applied to inlet 225, duringa compression stroke of electronically controlled damper link 14. For agiven spring 215, higher control pressure at inlet 225 will result inhigher bypass pressure required to open the remotely controllable valve200 and correspondingly higher damping resistance in electronicallycontrolled damper link 14. In one embodiment of sway bar system 100, theremotely controllable valve 200 is open in both directions when thepiston 205 is “topped out” against valve body 204. In another embodimentof sway bar system 100 however, when the piston 205 is abutted or“topped out” against valve body 204 the spring 215 and relativedimensions of the remotely controllable valve 200 still allow for thecone-shaped member 212 to engage the valve seat thereby closing theremotely controllable valve 200. In such an embodiment of sway barsystem 100, backflow from the rebound portion 103 of the damper cylinder141 to the compression portion 104 is always substantially closed andcracking pressure is determined by the pre-compression in the spring215. In such embodiment, additional fluid pressure may be added to inlet225 through port to increase the cracking pressure and thereby increasecompression damping through electronically controlled damper link 14over that value provided by the spring compression “topped out.”

FIG. 6 shows remotely controllable valve 200 in a closed position (whichit assumes during a rebound stroke of electronically controlled damperlink 14). As shown, the cone-shaped member 212 is seated against seat217 due to the force of the spring 215 and absent an opposite force fromfluid entering the remotely controllable valve 200 from electronicallycontrolled damper link 14. As cone-shaped member 212 telescopes out, agap 220 is formed between the end of the shaft 210 and an interior ofcone-shaped member 212. A vent 221 is provided to relieve any pressureformed in the gap 220. With the fluid path 201 closed, fluidcommunication is substantially shut off from the rebound portion 103 ofelectronically controlled damper link 14 into the valve body 204 (andhence through electronically controlled damper link 14 back to thecompression portion 104 is closed) and its “dead-end” path is shown byarrow 219.

Inlet 225 is formed in the valve body 204 for operation of the remotelycontrollable valve 200. In one embodiment, inlet 225 may be pressurizedto shift the remotely controllable valve 200 to a third or “locked-out”position. In FIG. 7, remotely controllable valve 200 is shown in thelocked-out position, thereby preventing fluid flow throughelectronically controlled damper link 14 in either direction regardlessof compression or rebound stroke. In the embodiment shown, inlet 225provides a fluid path 230 to a piston surface 227 formed on an end ofthe piston 205, opposite the cone-shaped member 212. Specifically,activating pressure is introduced via inlet 225 to move the piston 205and with it, cone-shaped member 212 toward seat 217. Sufficientactivating pressure fully compresses the spring 215 (substantial stackout) and/or closes the gap 220 thereby closing the cone-shaped member212 against the seat, sealing electronically controlled damper link 14to both compression flow and rebound flow. In the embodiment shown,remotely controllable valve 200 can be shifted to the third, locked-outposition from either the first, open position or the second, closedposition. Note that, when in the “locked out” position, remotelycontrollable valve 200 as shown, will open to compression flow when thecompression flow pressure acting over the surface area of thecone-shaped member 212 exceeds the inlet 225 pressure acting over thesurface area of the piston 205. Such inlet 225 pressure may be selectedto correspond therefore to a desired compression overpressure reliefvalue or “blow off” value thereby allowing compression bypass under“extreme” conditions even when electronically controlled damper link 14is “locked out”.

In the embodiment illustrated, remotely controllable valve 200 isintended to be shifted to the locked-out position with control fluidacting upon piston 205. In one embodiment, the activating pressure viainlet 225 is adjusted so that remotely controllable valve 200 is closedto rebound fluid (with the cone-shaped member 212 in seat 217) but withthe spring 215 not fully compressed or stacked out. In such a position,a high enough compression force (e.g. compression flow) will still openremotely controllable valve 200 and allow fluid to pass through remotelycontrollable valve 200 in a compression stroke. In one arrangement, theactivating pressure, controlled remotely, may be adjusted between levelswhere the lock-out is not energized and levels where the lock-out isfully energized. The activating pressure may also be adjusted atintermediate levels to create more or less damping resistance throughelectronically controlled damper link 14. The activating pressure may becreated by hydraulic or pneumatic input or any other suitable pressuresource.

In one example of sway bar system 100, remotely controllable valve 200is moved to a locked-out position and the electronically controlleddamper link 14 is stiffened by remote control from a simpleoperator-actuated switch located in the passenger compartment of thevehicle. In one embodiment of sway bar system 100, fluid pressure forcontrolling (e.g. locking-out) remotely controllable valve 200 isprovided by the vehicle's on-board source of pressurized hydraulic fluidcreated by, for example, the vehicle power steering system. In oneembodiment, pneumatic pressure is used to control (e.g. close) remotelycontrollable valve 200 where the pneumatic pressure is generated by anon-board compressor and accumulator system and conducted to remotelycontrollable valve 200 via a fluid conduit. In one embodiment of swaybar system 100, a linear electric motor (e.g. solenoid), or othersuitable electric actuator, is used, in lieu of the aforementioned inlet225 pressure, to move “piston 205” axially within valve body 204. Ashaft of the electric actuator (not shown) may be fixed to the piston205 such that axial movement of the shaft causes axial movement ofpiston 205 which in turn causes movement of cone-shaped member 212 (andcompression of spring 215 as appropriate). In one embodiment, theelectric actuator is configured to “push” piston 205 towards a closedposition and to “pull” piston 205 away from the closed positiondepending on the direction of the current switched through the actuator.

As in other embodiments, remotely controllable valve 200 may be solenoidoperated or hydraulically operated or pneumatically operated or operatedby any other suitable motive mechanism. Remotely controllable valve 200may be operated remotely by a switch 415 or potentiometer located in thecockpit of a vehicle or attached to appropriate operational parts of avehicle for timely activation (e.g. brake pedal) or may be operated inresponse to input from a microprocessor (e.g. calculating desiredsettings based on vehicle acceleration sensor data) or any suitablecombination of activation means. In a like manner, a controller for theadjustable pressure source (or for both the source and the valve) may becockpit mounted and may be manually adjustable or microprocessorcontrolled or both or selectively either.

In one embodiment of sway bar system 100, a pressure intensifier damperarrangement is located within the fluid path such that thesolenoid-controlled valve controls flow through that auxiliary damperwhich is then additive with the damper mechanism of the damping piston.In one embodiment of sway bar system 100, the damper mechanism of thedamping piston comprises a pressure intensifier. In one embodiment oneor both of the dampers comprise standard shim type dampers. In oneembodiment one or both of the dampers include an adjustable needle forlow speed bleed. In one embodiment, a blow off (e.g. checking poppettype or shim) is included in one of the flow paths or in a thirdparallel flow path.

FIG. 8 is a schematic diagram illustrating a control arrangement 400used to provide remote control of a remotely controllable valve 200using a vehicle's power steering fluid 410 (although any suitable fluidpressure source may be substituted for power steering fluid 410 as couldbe an electrical current source in the case of a remotely controllablevalve 200). As illustrated, a fluid pathway 405 having a switch-operatedvalve (and/or pressure regulator) 402 therein runs from power steeringfluid 410 (or an electrical current) that is kept pressurized by, in oneembodiment, a power steering pump (not shown) to a remotely controllablevalve 200 that is operable, for example, by a user selectable dash boardswitch 415. The switch-operated valve 402 permits fluid to travel toremotely controllable valve 200, thereby urging it to a closed position.When switch 415 is in the “off” position, working pressure withinelectronically controlled damper link 14, and/or a biasing member suchas a spring or annular atmospheric chamber (not shown), returnselectronically controlled damper link 14 to its normally-open position(with or without residual spring compression as designed). In anotherembodiment, a signal line runs from switch 415 to a solenoid along anelectrically conductive line. Thereafter, the solenoid convertselectrical energy into mechanical movement (identified by item 405) andshifts a plunger of remotely controllable valve 200, thereby opening orclosing the valve or causing the plunger to assume some predeterminedposition in-between. Hydraulically actuated valving for use withadditional components is shown and described in U.S. Pat. No. 6,073,536and that patent is incorporated by reference herein in its entirety.

While the example of FIG. 8 uses fluid power for operating remotelycontrollable valve 200, a variety of means are available for remotelycontrolling a remotely controllable valve 200. For instance, a source ofelectrical power from a 12 volt battery could be used to operate asolenoid member, thereby shifting a piston 205 in remotely controllablevalve 200 between open and closed positions. Remotely controllable valve200 or solenoid operating signal can be either via a physical conductoror an RF signal (or other wireless such as Bluetooth, WiFi, ANT) from atransmitter operated by the switch 415 to a receiver operable on theremotely controllable valve 200 (which would derive power from thevehicle power system such as 12 volt).

Remotely controllable valve 200 like the one described above isparticularly useful with an on/off road vehicle. Operating a vehiclewith very compliant, conventional sway bar on a smooth road at higherspeeds can be problematic due to the springiness/sponginess of thesuspension and corresponding vehicle handling problems associated withthat (e.g. turning roll, braking pitch). Such compliance can causereduced handling characteristics and even loss of control. Such controlissues can be pronounced when cornering at high speed as a vehicle witha conventional compliant sway bar may tend to roll excessively. Withremotely operated electronically controlled damper link 14 dampening and“lock out” described herein, dampening characteristics of electronicallycontrolled damper link 14 can be adjusted, and as such, sway bar system100 can be completely changed from a compliantly dampened “springy”arrangement to a highly dampened and “stiffer” (or fully locked out)system ideal for higher speeds on a smooth road.

In one embodiment, where compression flow is completely blocked, closureof electronically controlled damper link 14 results in substantial “lockout” of the sway bar system 100 (sway bar system 100 is renderedessentially rigid except for the movement of fluid through shimmedvalve). In another embodiment where some compression flow is allowed,closure of electronically controlled damper link 14 (e.g., by closure ofremotely controllable valve 200) results in a stiffer but stillfunctional sway bar system 100.

In addition to, or in lieu of, the simple, switch operated remotearrangement of FIG. 8; the remotely controllable valve 200 can beoperated automatically based upon one or more driving conditions.

FIG. 9 illustrates, for example, a system including three variables:shaft speed, shaft position and vehicle speed. Any or all of thevariables shown may be considered by processor 502 in controlling thesolenoid in the remotely controllable valve 200. Any other suitablevehicle operation variable may be used in addition to or in lieu of thevariables 515, 505, 510 such as for example, a vehicle mountedaccelerometer (or tilt/inclinometer) data or any other suitable vehicleor component performance data. In one embodiment the position of piston105 within damper cylinder 141 is determined using an accelerometer tosense modal resonance of damper cylinder 141. Such resonance will changedepending on the position of the piston 105 and an on-board processor(computer) is calibrated to correlate resonance with axial position. Inone embodiment, a suitable proximity sensor or linear coil transducer orother electro-magnetic transducer is incorporated in the damper cylinder141 to provide a sensor to monitor the position and/or speed of thepiston 105 (and suitable magnetic tag) with respect to the dampercylinder 141. In one embodiment, the magnetic transducer includes awaveguide and a magnet, such as a doughnut (toroidal) magnet that isjoined to the cylinder and oriented such that the magnetic fieldgenerated by the magnet passes through shaft 24 and the waveguide.Electric pulses are applied to the waveguide from a pulse generator thatprovides a stream of electric pulses, each of which is also provided toa signal processing circuit for timing purposes. When the electric pulseis applied to the waveguide a magnetic field is formed surrounding thewaveguide. Interaction of this field with the magnetic field from themagnet causes a torsional strain wave pulse to be launched in thewaveguide in both directions away from the magnet. A coil assembly andsensing tape is joined to the waveguide. The strain wave causes adynamic effect in the permeability of the sensing tape which is biasedwith a permanent magnetic field by the magnet. The dynamic effect in themagnetic field of the coil assembly due to the strain wave pulse,results in an output signal from the coil assembly that is provided tothe signal processing circuit along signal lines. By comparing the timeof application of a particular electric pulse and a time of return of asonic torsional strain wave pulse back along the waveguide, the signalprocessing circuit can calculate a distance of the magnet from the coilassembly or the relative velocity between the waveguide and the magnet.The signal processing circuit provides an output signal, either digital,or analogue, proportional to the calculated distance and/or velocity. Atransducer-operated arrangement for measuring shaft speed and velocityis described in U.S. Pat. No. 5,952,823 and that patent is incorporatedby reference herein in its entirety.

While a transducer assembly located at electronically controlled damperlink 14 measures shaft speed and location, a separate wheel speedtransducer for sensing the rotational speed of a wheel about an axleincludes housing fixed to the axle and containing therein, for example,two permanent magnets. In one embodiment the magnets are arranged suchthat an elongated pole piece commonly abuts first surfaces of each ofthe magnets, such surfaces being of like polarity. Two inductive coilshaving flux-conductive cores axially passing therethrough abut each ofthe magnets on second surfaces thereof, the second surfaces of themagnets again being of like polarity with respect to each other and ofopposite polarity with respect to the first surfaces. Wheel speedtransducers are described in U.S. Pat. No. 3,986,118 which isincorporated herein by reference in its entirety.

While the examples illustrated relate to manual operation and automatedoperation based upon specific parameters, remotely controllable valve200 or the remote operation of a pressure source can be used in avariety of ways with many different driving and road variables. In oneexample, remotely controllable valve 200 is controlled based uponvehicle speed in conjunction with the angular location of the vehicle'ssteering wheel. In this manner, by sensing the steering wheel turnseverity (angle of rotation), additional dampening can be applied tostiffen electronically controlled damper link 14 thereby stiffening swaybar system 100 (suitable, for example, to mitigate cornering roll) inthe event of a sharp turn at a relatively high speed. In anotherexample, a transducer, such as an accelerometer, measures other aspectsof the vehicle's suspension system, like axle force and/or momentsapplied to various parts of the vehicle, like steering tie rods, anddirects change to electronically controlled damper link 14 and thus thecompliance or stiffness of sway bar system 100 in response thereto.

It should be noted that any of the features disclosed herein are usefulalone or in any suitable combination. While the foregoing is directed toembodiments of the present invention, other and further embodiments ofthe invention is implemented without departing from the scope of theinvention and the scope thereof is determined by the Claims that follow.

What we claim is:
 1. A sway bar system comprising: a sway bar having afirst end and a second end, said second end distal from said first end;a first link coupled to said first end of said sway bar and said firstlink configured to be coupled a first location of a vehicle, said firstlink electronically controlled, said first link comprising: a dampercylinder, said damper cylinder having a damper cylinder volume; adamping piston axially moveable within said damper cylinder; a shaftfixedly coupled to said damping piston; a fluid reserve cylinder, saidfluid reserve cylinder comprising: a fluid reservoir chamber; a gaschamber; and an internal floating piston fluidly separating said fluidreservoir chamber and said gas chamber; and a valve fluidly coupled tosaid damper cylinder and said fluid reserve cylinder, said valve havinga flow area wherein a ratio of said damper cylinder volume to said flowarea of said valve is adjustable; and a second link coupled to saidsecond end of said sway bar and said second link configured to becoupled a second location of said vehicle.
 2. The sway bar system ofclaim 1, wherein said flow area of said valve controls an amount offluid flow between said damper cylinder and said fluid reservoir chambervia said valve.
 3. The sway bar system of claim 1 wherein said valve isan electronic valve.
 4. The sway bar system of claim 1 wherein saidfirst link is configured to be coupled to said vehicle proximate a wheelof said vehicle.
 5. The sway bar system of claim 1 wherein said firstlink is configured to be coupled to said vehicle proximate an axle ofsaid vehicle.
 6. The sway bar system of claim 1 wherein said first linkis configured to be coupled to said vehicle proximate a suspensioncomponent of said vehicle.
 7. The sway bar system of claim 1 whereinsaid second link is electronically controlled.
 8. The sway bar system ofclaim 7 wherein said second link comprises: a damper cylinder, saiddamper cylinder having a damper cylinder volume; a damping pistonaxially moveable within said damper cylinder; a shaft fixedly coupled tosaid damping piston; a fluid reserve cylinder, said fluid reservecylinder comprising: a fluid reservoir chamber; a gas chamber; and aninternal floating piston fluidly separating said fluid reservoir chamberand said gas chamber; and a valve fluidly coupled to said dampercylinder and said fluid reserve cylinder, said valve having a flow areawherein a ratio of said damper cylinder volume to said flow area of saidvalve is adjustable.
 9. The sway bar system of claim 8 wherein saidsecond link is configured to be coupled to said vehicle proximate awheel of said vehicle.
 10. The sway bar system of claim 8 wherein saidsecond link is configured to be coupled to said vehicle proximate anaxle of said vehicle.
 11. The sway bar system of claim 8 wherein saidsecond link is configured to be coupled to said vehicle proximate asuspension component of said vehicle.
 12. A sway bar system comprising:a sway bar having a first end and a second end, said second end distalfrom said first end; a first electronically controlled damper linkcoupled to said first end of said sway bar and said first electronicallycontrolled damper link configured to be coupled a first location of avehicle; and a second link coupled to said second end of said sway barand said second link configured to be coupled a second location of saidvehicle.
 13. The sway bar system of claim 12 wherein said firstelectronically controlled damper link comprises: a damper cylinder, saiddamper cylinder having a damper cylinder volume; a damping pistonaxially moveable within said damper cylinder; a shaft fixedly coupled tosaid damping piston; a fluid reserve cylinder, said fluid reservecylinder comprising: a fluid reservoir chamber; a gas chamber; and aninternal floating piston fluidly separating said fluid reservoir chamberand said gas chamber; and a valve fluidly coupled to said dampercylinder and said fluid reserve cylinder, said valve having a flow areawherein a ratio of said damper cylinder volume to said flow area of saidvalve is adjustable.
 14. The sway bar system of claim 13, wherein saidflow area of said valve controls an amount of fluid flow between saiddamper cylinder and said fluid reservoir chamber via said valve.
 15. Thesway bar system of claim 13 wherein said valve is an electronic valve.16. The sway bar system of claim 12 wherein said first electronicallycontrolled damper link is configured to be coupled to said vehicleproximate a wheel of said vehicle.
 17. The sway bar system of claim 12wherein said first electronically controlled damper link is configuredto be coupled to said vehicle proximate an axle of said vehicle.
 18. Thesway bar system of claim 12 wherein said first electronically controlleddamper link is configured to be coupled to said vehicle proximate asuspension component of said vehicle.
 19. The sway bar system of claim12 wherein said second link comprises: a second electronicallycontrolled damper link.
 20. The sway bar system of claim 13 wherein saidsecond electronically controlled damper link comprises: a dampercylinder, said damper cylinder having a damper cylinder volume; adamping piston axially moveable within said damper cylinder; a shaftfixedly coupled to said damping piston; a fluid reserve cylinder, saidfluid reserve cylinder comprising: a fluid reservoir chamber; a gaschamber; and an internal floating piston fluidly separating said fluidreservoir chamber and said gas chamber; and a valve fluidly coupled tosaid damper cylinder and said fluid reserve cylinder, said valve havinga flow area wherein a ratio of said damper cylinder volume to said flowarea of said valve is adjustable.
 21. The sway bar system of claim 22,wherein said flow area of said valve of said second electronicallycontrolled damper link controls an amount of fluid flow between saiddamper cylinder of said second electronically controlled damper link andsaid fluid reservoir chamber of said second electronically controlleddamper link via said valve of said second electronically controlleddamper link.
 22. The sway bar system of claim 20 wherein said valve ofsaid second electronically controlled damper link is an electronicvalve.
 23. The sway bar system of claim 19 wherein said secondelectronically controlled damper link is configured to be coupled tosaid vehicle proximate a wheel of said vehicle.
 24. The sway bar systemof claim 19 wherein said second electronically controlled damper link isconfigured to be coupled to said vehicle proximate an axle of saidvehicle.
 25. The sway bar system of claim 19 wherein said secondelectronically controlled damper link is configured to be coupled tosaid vehicle proximate a suspension component of said vehicle.
 26. Asway bar system comprising: a sway bar having a first end and a secondend, said second end distal from said first end; a first electronicallycontrolled damper link coupled to said first end of said sway bar andsaid first electronically controlled damper link configured to becoupled a first location of a vehicle, wherein said first electronicallycontrolled damper link comprises: a damper cylinder, said dampercylinder having a damper cylinder volume; a damping piston axiallymoveable within said damper cylinder; a shaft fixedly coupled to saiddamping piston; a fluid reserve cylinder, said fluid reserve cylindercomprising: a fluid reservoir chamber; a gas chamber; and an internalfloating piston fluidly separating said fluid reservoir chamber and saidgas chamber; and a valve fluidly coupled to said damper cylinder andsaid fluid reserve cylinder, said valve having a flow area wherein aratio of said damper cylinder volume to said flow area of said valve isadjustable; and a second electronically controlled damper link coupledto said second end of said sway bar and said second electronicallycontrolled damper link configured to be coupled a second location ofsaid vehicle.
 27. The sway bar system of claim 26 wherein said secondelectronically controlled damper link comprises: a damper cylinder, saiddamper cylinder having a damper cylinder volume; a damping pistonaxially moveable within said damper cylinder; a shaft fixedly coupled tosaid damping piston; a fluid reserve cylinder, said fluid reservecylinder comprising: a fluid reservoir chamber; a gas chamber; and aninternal floating piston fluidly separating said fluid reservoir chamberand said gas chamber; and a valve fluidly coupled to said dampercylinder and said fluid reserve cylinder, said valve having a flow areawherein a ratio of said damper cylinder volume to said flow area of saidvalve is adjustable.
 28. A vehicle and sway bar system comprising: avehicle; a sway bar having a first end and a second end, said second enddistal from said first end; a first electronically controlled damperlink coupled to said first end of said sway bar and said firstelectronically controlled damper link coupled to a first location ofsaid vehicle; and a second link coupled to said second end of said swaybar and said second link coupled to a second location of said vehicle.